the future until a consistent federal standard for PFAS, which is also acceptable to state regulators, is enacted. A quick resolution to this problem is not expected. Once released into the environment, some PFAS have been shown to be relatively mobile and most have been found to be stable and per- sistent. At the current time, remediation of soil containing PFAS has been limited largely to landfilling and incineration. Incineration is an expensive process, particularly if the soil must be transported great dis- tances to the location of an incinerator that is permitted for incineration of PFAS. It is expected that landfills will be more reluctant to accept PFAS-containing material as they become required to deal with PFAS present in their leachate. In situ remediation of PFAS in groundwater is not currently feasible, and due to the chemical stability of PFAS molecules, in situ destructive technologies for PFAS in groundwater is likely to be very challeng- ing. Technologies are available for adsorbing and containing PFAS in place within an aquifer. This approach can be effective for containing PFAS and preventing its spread through a broader area of an aquifer. However, these technologies do not destroy the PFAS in the aquifer, but merely hold them in place. For the present time, the most effective approach for containing and treating PFAS in groundwater is a pump-and-treat system. These sys- tems can contain a plume of PFAS in groundwater and allow removal of the PFAS at the ground surface, through a variety of readily avail- able treatment technologies. The treated groundwater can be used as a drinking water source, released to a surface water body or reinjected into the aquifer. The most commonly used technologies for treating PFAS in water are granular activated carbon (GAC), ion exchange resins, and membrane technologies. Of these technologies, GAC is the most prevalent at this time and is effective for removal of some of the most commonly encountered PFAS. Ion exchange resins have been shown to be effective for a wide range of PFAS compounds and research is ongoing to improve the range of PFAS treated and the ca- pacity of the ion exchange resins. Membrane technologies, such as nanofiltration and reverse osmosis are quite effective for removal of a broad range of PFAS but can be costly to implement and operate and will also result in the generation of a waste stream that still contains the removed PFAS in a concentrated form.
substances, developing interim remediation standards, establishing state/local authorities as the first line of enforcement, finalizing toxic- ity assessments for and values for some additional PFAS chemicals, completing a significant new use restriction (SNUR) analysis under the Toxic Substance Control Act, considering the addition of PFAS to Toxics Release Inventory (TRI) reporting, and developing consistent informational materials across various governmental agencies. In the absence of quick action and clear leadership at the federal level, individual states have enacted their own regulations with respect to drinking water and in some cases biosolids and soils. This has resulted in a patchwork of varying standards and health advisories across the country, with those states that have established more stringent levels for the presence of PFAS in environmental media taking the lead role in enforcement. This presents a difficult environment for the regu- lated community with varying standards being applied throughout the country and being implemented under different timetables. It appears this challenging regulatory environment will remain in place well into References Agency for Toxic Substances and Disease Registry (ATSDR), Toxicological Profile for Perfluoroalkyls (June 2018). https://www.atsdr.cdc.gov/toxprofiles/tp200.pdf. Agency for Toxic Substances and Disease Registry (ATSDR), accessed May 14, 2020. Per- and Polyfluoroalkyl Substances (PFAS) and Your Health. https://www.atsdr.cdc.gov/pfas/index.html. Interstate Technology and Research Council (ITRC), 2020. PFAS Technical and Regulatory Guidance Document and Fact Sheet PFAS-1. Washington, D.C.: Interstate Technology and Research Council, PFAS Team. https://pfas-1.itrcweb.org/. United States Environmental Protection Agency (USEPA), November 2016. Drinking Water Health Advisory for Perfluorooctanoic acid (“PFOA”) and Perfluorooctane sulfonate (“PFOS”). https://www.epa.gov/sites/production/files/2016-05/ documents/pfoa_health_advisory_final_508.pdf, https:// www.epa.gov/sites/production/files/2016-05/documents/ pfos_health_advisory_final_508.pdf. United States Environmental Protection Agency (USEPA), accessed May 14, 2020. Per- and Polyfluoroalkyl Substances (PFAS). https://www.epa.gov/pfas.
JAMES PEEPLES, Vice President & Senior Technical Environmental Engineer at T&M Associates.
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may 2020
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